Exemplary embodiments of the present invention relate to a method to prevent a collision of a vehicle and a driver assistance system for a vehicle to carry out the method.
Such methods and driver assistance systems are already known. European patent document EP 1 057 159 B1 discloses a method to prevent a collision of a vehicle with an obstacle arranged before the vehicle. In the method, a first distance between the vehicle and the obstacle is calculated, which is at least required in order to prevent a collision of the vehicle with the obstacle through a braking procedure with maximum deceleration. Furthermore, a second distance is calculated, which is at least required in order to prevent a collision of the vehicle with the obstacle through steering the vehicle past the obstacle. An automatic braking procedure is then only initiated if the detected distance is both smaller than the first calculated distance and smaller than the second calculated distance, i.e. if the driver can neither prevent the collision by braking nor by deviation, and if the degree of contact of the vehicle relative to the obstacle exceeds a predetermined threshold. A driver activity, a status of a road, a loading condition and the degree of contact of the vehicle relative to the obstacle are included in the calculation.
German patent document DE 10 2004 056 027 A1 discloses a method to prevent collisions or lessen the severity of a collision of a vehicle with the steps: detecting the speed and the direction of movement of the vehicle; detecting the position of objects in the vehicle surroundings; detecting the speed and the direction of movement of the objects relative to the vehicle; predicting the future position of the objects relative to the vehicle; evaluating the present and future positions of the objects relative to the vehicle; emitting a warning to the driver and/or carrying out an automatic steering and/or braking intervention through an assistance system of the vehicle, depending on the evaluation, if a collision with the object is inevitable without a system intervention according to the evaluation. The evaluation is based on the calculation of two action time periods (time-to-brake and time-to-avoid), the remaining time until the last moment for the initiation of a braking intervention to prevent collision or for the initiation of an evasion maneuver to prevent collision.
Exemplary embodiments of the present invention are directed to an improved method to prevent a collision of a vehicle, as well as a driver assistance system for a vehicle to carry out the method.
In the method according to the invention to prevent a collision of a vehicle, an operation of a brake pedal of the vehicle is continuously detected and a risk of collision is concluded if the brake pedal is operated with an operating speed, which exceeds a predetermined minimum operating speed, and at an operating value, which exceeds a predetermined minimum operating value. Furthermore, a position and a movement of objects in the vehicle surroundings relative to the vehicle are detected and evaluated regarding the risk of collision. When a risk of collision has been detected, an evasion maneuver of the vehicle is automatically carried out if the evaluation of the risk of collision reveals that a collision can be prevented by an evasion maneuver but not by a braking maneuver.
According to the invention, an automatic evasion maneuver of the vehicle is thus initiated if a threatening collision is recognized, which can only still be prevented through an evasion maneuver, but no longer through a braking maneuver. According to the invention, braking maneuvers thus take preference over evasion maneuvers. Thus it is advantageously taken into account that evasion maneuvers are, as a rule, more risky than braking maneuvers, as an evasion maneuver can cause further risks of collision, for example with on-coming traffic, and can more easily lead to the driver losing control of the vehicle.
According to the invention, a risk of collision is furthermore recognized through a quick operation of the brake pedal of the vehicle and is evaluated due to the position and movement of objects in the vehicle surroundings. Therein it is assumed that a quick operation of the brake pedal signals a danger of collision, as drivers tend to prevent a threatening collision through sharp braking Through the detection and evaluation of the position and movement of objects in the vehicle surroundings, it can be advantageously calculated whether the risk of collision actually exists and whether it can be prevented by braking or evasion of the vehicle.